Sad news regarding Diem Brown of MTV's 'The Challenge,' as it's been revealed that the reality star is battling cancer for the third time.

Us Weekly reports that Brown was filming in Panama for the upcoming season when she collapsed on set. She was airlifted and rushed to New York City where she underwent two emergency surgeries. Brown learned that she had colon cancer and had the mass removed.

Brown was first diagnosed with ovarian cancer at the age of 22. After beating it with chemotherapy, she learned in 2012 that the cancer had returned and it was likely that she would not live until 2013. Brown then announced that the cancer was gone in Feb. of 2013.

She told Us Weekly at the time, "I can't stop smiling from ear to ear. I feel so free, like I have my life as my own again."

Brown added, "I can't describe the feeling of doctors telling you your cancer is gone, especially when you were told this day more than likely would never come. I love it when those doctors are wrong."

In addition to appearing on the MTV show, Brown also created the site MedGift, which allows people to donate money and gifts to patients receiving treatment. You can support Brown by donating on her page here.

We wish Brown all the best, as well as a speedy recovery.